Youth substance use and abuse is a major public health problem contributing to significant levels of psychosocial and physical health morbidity. One group identified to have elevated rates of substance use and substance disorders is sexual minority youth. Despite the fact that these youth face distinct risks, little is know about how minority sexual orientation development, in conjunction with individual factors (e.g., depression, suicidality) and other contextual experiences (e.g. family, peer, school, and community contexts), influence developmental trajectories of substance involvement over adolescence and young adulthood. Furthermore, empirical efforts to identify developmental processes and other factors supporting positive adaptation in this population are only beginning. My long range goal is to conduct research that advances understanding of the pathways to the development of substance involvement, co-occurring mental health and social problems, and resilience and adaptation in sexual minority youth. My career development plan proposes additional training and mentorship in three areas critical to my growth as an independent researcher: (1) developmental psychology with a focus on contemporary conceptualizations and findings about adolescent and pre-adolescent normative development;(2) child/adolescent psychopathology with an emphasis on substance use and co-occurring mental health disorders and resilience processes;and (3) the application of emerging statistical methods for studying questions of a developmental nature (e.g., latent growth modeling). My research plan includes 3 aims: (1) characterizing longitudinal patterns of substance use trajectories during adolescence and young adulthood in sexual minority youth;(2) identifying salient individual-level and contextual-level factors that contribute to the disproportionate substance involvement in this population;and (3) exploring adaptation and resilience in young adulthood in relation to vulnerability and protective factors occurring during childhood and adolescence among sexual minority youth. The proposed career development plan will provide the necessary training and knowledge to support an R01 application in which I further aim to clarify underlying mechanisms to substance involvement and resilience pathways in sexual minority youth for informing efforts to enhance their positive development and reduce their risk of developing poor health outcomes.